Fixturing a thin plate so that at least one side can be precision machined without any fixture or machining-induced deformations can be difficult. Current best practice is to double disk grind the plates so they are as flat as economically reasonable, and then machine the plates. However, the cost and final accuracy (flatness) achieved can be improved upon. For example, flat pin chucks are commonly used in the semiconductor industry to support silicon wafers while allowing them to be held down by vacuum so a top surface of the wafers can be processed. Flatness is of extreme concern and the pin tops are lapped flat to a plane. The pin chucks generally have a rectangular cross section that allows them to be arranged in an array. Unfortunately, the time and labor involved in lapping each of the pin chucks to a precise height can be both time consuming and expensive.